Crosslinked terpolymers obtained without sulfur and vulcanizing agents and method for preparing same

ABSTRACT

Terpolymers are disclosed which are subject to crosslinking in the absence of any vulcanizing agent or accelerator and which are obtained from Alpha -olefine monomers and a terpolymer having side chains consisting of a GROUP WHICH IS DIRECTLY LINKED TO TWO CARBON ATOMS, EACH OF WHICH HAS AN ETHYLENIC BOND, E.G.: WHEREIN R1, R2, R3, R4, R5, and R6 are selected from the group consisting of hydrogen and hydrocarbon radicals which contain from one to five carbon atoms and which may include pairs of radicals that may be cyclized to form one or more rings having from four to seven carbon atoms.

United States Patent Corradini et al.

[54] CROSSLINKED TERPOLYMERS OBTAINED WITHOUT SULFUR AND VULCANIZING AGENTS AND METHOD FOR PREPARING SAME [72] Inventors: Giorgio Corradini; Giuseppe Ghetti;

Sabastiano Cesca, all of San Donato Milanese; Sergio Arrighetti, Mila all of Italy 1 1 Assignw s'nr 2ro ee1,s -rA-1 a Italy [22] Filed: April 23, 1970 [21] Appl. No.: 31,410

[30] Foreign Application Priority Data 1 1 Sept. 12, 1972 Primary Examiner-Joseph L. Schofer Assistant Examiner-Roger S. Benjamin Attorney-Ralph M. Watson [5 7] ABSTRACT Terpolymers are disclosed which are subject to crosslinking in the absence of any vulcanizing agent or accelerator and which are obtained from a-olefine monomers and a terpolymer having side chains consisting of a T CH- or -CH2 group which is directly linked to two carbon atoms, each of which has an ethylenic bond, e.g.:

wherein R R R R R and R are selected from the group consisting of hydrogen and hydrocarbon radicals which contain from one to five carbon atoms and which may include pairs of radicals that may be cyclized to form one or more rings having from four to seven carbon atoms.

1 1 Claims, No Drawings CROSSLINKED TERPOLYMERS OBTAINED WITHOUT SULFUR AND VULCANIZING AGENTS AND METHOD FOR PREPARING SAME The present invention refers to new crosslinked terpolymers which do not contain sulfur and the method for preparing same.

It is well known that the crosslinking of polymers, namely hydrocarbon elastomers containing double bonds along the molecule, is carried out by incorporating into the polymer itself some chemical ingredients, such as sulfur, accelerators, zinc oxide, stearic acid and so on which generally, at high temperatures (usually higher than 100 C), form crosslinkings among the polymeric chains causing the obtained productto loose the plastic behavior to assume an elastic one.

Moreover it is known that the crosslinking of polymers, particularly of elastomers may or may not contain double bonds along the molecule, can take place by incorporating into the polymer itself peroxides even when mixed with other chemical ingredients, which at high temperatures (generally higher than 100 C) form crosslinkings among the polymeric chains.

However it is well known that either the use of active accelerators and sulfur containing vulcanizing agents or the use of peroxide type vulcanizing agents causes a remarkable increase of the production cost of the finished crosslinked polymer.

We have now found new polymers which are vulcanized in the absence of any vulcanization ingredient obtained from linear polymers having side chains consisting of a or -C1-l group which is directly linked to two carbon atoms both of them belonging to an ethylenic double bond.

This group may be exemplified as follows:

wherein R R R R R and R may be either hydrogen or hydrocarbon radicals having one to five carbon atoms; furthermore the radicals R to R may be, two by two, one or more divalent radicals, so that they form one or more rings having four to seven carbon atoms.

The above structure may be a cyclopentadiene ring when the two utmost carbon atoms of the group are joined together. The polymers according to the present invention may be preferably obtained by copolymerizing two a-olefms, especially ethylene and propylene, with a polyene having the aforesaid groups in addition to a double bond which is engaged in building the macromolecule.

Nonlimiting examples of termonomers useful for the preparation of crosslinked polymers according to the present invention are those described in copending U. S. patent applications, Ser. No. 855,771, filed Sept. 5, 1969, and Ser. No. 886,390, filed Dec. 18, 1969, in the Italian patent application No. 25242 A/68. The preparation of terpolymers according to the invention may be favorably carried out by employing the following termonomers:

wherein R and R may be hydrogen or alkyl radicals. According to the present invention the crosslinking of terpolymers or polymers is merely carried out by heating them at a temperature of C to 250C in a conventional apparatus for a period of 2 to 200 minutes.

Some different extenders may be added to the polymer, for example carbon black, silica, kaolin, calcium carbonate, and so on, and/or parafiin oils, aromatic and naphtenic oils which are commonly employed in the rubber industry.

The following examples are given by way of illustration but do not limit at all the present invention.

EXAMPLE 1 a. An ethylene-propylene-dehydrodicyclopentadiene terpolymer has been synthesized according to the following process: 1,000 cc of n-hexane are introduced, in an inert atmosphere, into a 1,500 cc tubular reactor provided with a mechanical stirrer, thermometric sheath and a jacket for the thermostating fluid. At the same time a mixture of ethylene and propylene, having a molar ratio of 2:1, is introduced into the reactor bottom with a flow of 1200 Nllh; in order to facilitate the reaching of the equilibrium of saturation, the solvent is vigorously stirred, while its temperature is kept at -20 C by a freezing mixture circulating through the reactor jacket and whose temperature is controlled by a cryostat. The equilibrium conditions can be presumed to be reached in about twenty minutes of bubbling the monomers mixture. Thereafter 1.8 mmoles/lt of (C 11,) 2 AlCl, 0.9 mmoles/lt of anisole and 0.75 mmoles/lt of dehydrodicyclopentadiene (5,2,1,0 7a, 3a decatriene 3,5, 7a); are introduced into the reactor; while the stream of the gaseous monomers is flowing, the reaction of polymerization is started by a further introduction of 0.3 mmoles/lt of VCl The polymerization is carried out for 10 minutes: 0.75 mmoles/lt per minute of dehydrodicyclopentadiene being added.

The reaction is stopped by introducing into the reactor 1 cc of n-butanol. The reaction solution is washed with an aqueous solution of HG and then with water up to neutrality; then it is coagulated by slowly pouring it into an excess of acetone, to which an aminic antioxidant (AG-4010) has been added.

After drying at 50C at reduced pressure for 15 h an elastomeric mass is obtained; having the appearance of unvulcanized rubber and weighing 38.2 gr. At X-rays analysis it was entirely amorphous and showed an ethylene content of 59% b.w., whereas the determination of the intrinsic viscosity effected in toluene at 30C gave a value of [IL] =2.l2 dl/gr.

The determination of the dehydrodicyclopentadiene, effected by iodometric way, gave a value of 1.39% b.w.

b. The sample, prepared as above, was heated in a press at 190C for 20 minutes, after it was become homogeneous by mixing it in an open mill at room temc. In an open mill and at room temperature some carbon black (l-IAF) has been added to the sample, obtained according to the point(a), at a ratio I-IAF/polymer of 1:2; the obtained mixture has been heated in a press at 190C. for 20 minutes; some dumbell test pieces have been obtained therefrom; subjected, to tensile stress test they gave the results of Table 11. In the same table we report the results obtained with conventional commercial polymers, subjected to the same treatment as described in the present point(c).

The reported data show that the sample RN 5 is vulcanized whereas the samples A, B, C, D, are not vulcanized: moduli and maximum tensile stresses of the former are very high whereas the elongation at break values, very low for A, B, C, D, are similar to those of the mixes of EPDM containing carbon black and not vulcanized.

perature and no ingredient having been added. Some dumbell test pieces obtained from the moulded small, 30 when: subjected to tensile stress test, gave the results of the Table 1. In the same table there are reported the results obtained with conventional EPDM terpolymers, subjected to the same treatment as described in the d. In an open mill and at room temperature some carbon black (HAF) was added to the sample, obtained according to the point(a), at a ratio HAP/polymer of 1:2; the mixture was heated in a press at various temperatures for different periods. Some dumbell test pieces have been obtained from the moulded plates;

present point (b). 35 they gave the results set forth in Table III.

TABLE III Polymer, added with carbon black HAF (50 p.p.e.), at 120 (3., 145 0., 100 C.

Terpolymer Temperlnwing as ntnre Time M 100% M 200% M 300% CR AR 1. set monomer C.) (111111.) (kg/em?) (kgJcmJ) (kg/cm!) (kg/cm!) (percent) (percent) 16 121) 17 120 30 22 25 215 20 120 25 44 86 144 415 29 RN 5 5 22 23 24 210 25 145 15 32 49 77 90 365 37 30 53 89 113 365 33 60 37 81 166 206 360 17 2 26 42 72 122 440 5 2B 53 104 170 415 25 100 10 33 60 133 177 360 17 20 35 82 164 193 325 13 120 30 03 176 260 3 The reported data show that the sample RN 5 is vul- EXAMPLE 2 canized whereas the samples A, B, C, D are not vulcanized. This fact particularly results from the moduli 100 percent and 150 percent, indicative for the vulcanization degree which are very much higher for RN a. An ethylene-propylene-dehydrodicyclopentadiene terpolymer was synthesized according to the process described in Example 1, paragraph a), using:

5; from the elongations at break, very much higher for 55 exam 1000 the samples A, B, C, D and from the permanent set, vc]4 0.4 mmoles very much lower for RN 5. C,H, ,A|c| 2.4 mmoles TABLE 1 Polymers heated in press at 190 C. for 20 minutes Ethylene Terpolymer having Tcrmonomer (percent [1;]tol M 100% M 150% CR AR P. set as monomer (mole/kg.) by weight) 30 C. (kg/em?) (kg/cm!) (kg/cm!) (percent) (percent) 0.107 50 2. 12 10 26 28 165 0 0. 470 58 1. 78 5 4 2 3000 XML 0. 630 63 1. (i3 6 6 5 1600 235 0. 44 65 1. 65 8 E) 10 1100 105 0. 47 60 1. 6 6 4 1000 wherein RN 5 is (lvl1ydrodii'yelopuntmiieno or 5,2.l.0-3a,7n i0t11triuno-3,5,7n; A is 1,4 hexadivno; I1 is 0thylidennorhornmie; G=1li elongation;

sg fgf do enmdiene f :23 b. The sample, obtained according to the point a), Tem peraturi p es has been treated in a press at 190C. for 20 minutes, can cm. 2.0 mmoles it; the after it had become homogeneous by mixing it in an gaseous p ase polymefimionumc 4 minutes open mill at room temperature. Tensile stress data,

5 from the dumbell test pieces obtained from the plates molded as above, are given on the Table V.

c. The sample, obtained according to the point(a),

has been treated at l90C. for 20 minutes, after it had At the end of the reaction and after drying 18.3 g of amorphous elastomer were obtained; they show the following propertle been mixed with carbon black I-IAF (50 parts for 100 parts of polymer) at room temperature in an open mill. 3235:3 3 zgg b w j 47 On the Table VI there are reported the tensile stress i gg'i (inymluene' data on the dumbell test pieces obtained from the at 30C.) 2.65 dI/gr. molded plates.

TABLE V Treating the polymer alone at 190 C. for minutes Tel-polymer having as v Termonomer 02114 [1 1 tol M 100% M 2007 CR AR P. set monomer (mole/kg.) (pigment C. (kg/cm!) (kg/cm!) (kg/cm?) (percent) (percent) RN 5 0.174 v 57 1.63 13 16 23 260 4 TABLE VI Treating the polymer, added with carbon black (60 p.p.c.) at 190 C for 20 minutes Terpolymer having as M 50% M 200% CR AR P. set monomer (kg/cmfi) (kg/cm!) (kg/cm?) (percent) (percent) b. The sample, obtained as above, was mixed with 30 carbon black I-IAF (50 parts for 100 parts of polymer) in an opened mill, at room temperature; it was then divided into two parts which have been heated in a press respectively at 190C. for 10 minutes and at 145C. for 30 minutes.

Tensile stress data, from the dumbell test pieces ob- EXAMPLE 4 a. An ethylene-propylene-2-norbon-5 -enyl-4(or 5 cyclopentadienyl-methane terpolymer was synthesized according to the process described in the Example 1,

paragraph a) using:

Toluene 1000 cm tamed from the molded plates, are given on the Table vommcfloh 0'8 mmoles IV. I (C,H,),AlCl s mmoles TABLE IV Polymer added with carbon black IIAF p.p.c.) at 190 C. for 20 minutes Terpolyrner having Termonomer (perc ent [1 1ml Temp. Time M 50% M 200% CR AR 1. set as monomer (mole/kg.) b.w.) 30 0. 0.) (min.) (kg/cm!) (kg/cm?) (kg/cm!) (percent) (percent) EXAMPLE 3 2-norbon-5-enyl-4'(or 5)- cyclo-pentadienyl-methane 5.5 mmoles (1.8 mmoles were introduced at the beginning and the rest was added minute by minute along the reaction time) 2.0 mmoles in the I a. An ethylene-propylene-dehydrodicyclopentadiene terpolymer was synthesized according to the process described'in the Example 1, paragraph 1, using: c "dc H gaseous VO(O-n-C,H,), 1.2 mmoles phase (C,H ),AlCl 12.0 mmoles Temperature Toluene 1000 cm Polymerization time 10 minutes C,l-IJC,H. 2.0 (moles in the gaseous phase) Dehydrodicyclopentodiene l5.0 mmoles (1.5 mmoles After the reacnon sohmon had beenpoagulated and added minute y the produced polymer had been dried, 12.6 g of Temperature 0T. elastomer were obtained; at X rays examination it was Reaction time lorninutes entirely amorphous, and it showed the properties given on the Table VII.

28.8 g. of elastomers were obtained after coagulating b. Some carbon black HAF was added to the sample and drying; at X rays examination it was entirely amorphous, and it shows the properties given on' the Table V.

obtained according to the above point a) in an open mill, at room temperature, at a ratio HAF/elastomer of 1:2; afterwards it was molded at the temperature of ,7 8.- 120C., 143C, 190C. during periods, respectively, of zp f 15 30 120 minutes, 15 30 60 minutes, 2 5 ,5.?f" 16 $213 20 120 minutes. can/0,. 2.0 mnoles in the gase- On the Table VII are reported the tensile stress data 5 P referring to the dumbell test pieces obtained from the gig gzzggzl 3.2 molded plates. Reaction time is minutes TABLE v11 Polymer, added with carbon black HAF (50 p.p.c.) and heated at 120 0., 190 C.

Terpolymer CzHi emperhaving as Termonomer (percent l'r ltol ature Time M 50% M 100% M 200% CR AR P. set termonomer (mole/kg.) b. w.) 30 C. C.) (mim) (kg/em!) (kgJcmJ) (kgJcmJ) (kg./em.) (percent) (percent) 15 28 as so 4 120 30 21 so 130 s 120 22 92 210 s 5 1s 34 155 4 145 5 21 as 210 1:; H11 0. 233 59 1.98 28 3% H1 38 g 2 11 74 305 is 5 18 m7 ass is 190 10 144 290 13 2o 20 228 360 1a 120 24 224 28a 0 NOTE: Hu=2-norbor-5-enyl-4' (or 6')-eyclopentadienyl-xnethnne.

EXAMPLE 5 a. An ethylene-propylene-2-norbor-5-enyl-2'(or 3')- methyl-4'(or 5')-cyclopentadienyl-methane was synthesized according to the process described in the Example 1 using:

n-heptane 1000 run V( Acetylacetonate), 0.4 nmoles (C,H,,),AICI 3.2 nmoles C,HJC,H, 2.0 mnoles in the gaseous phase 2-norbor-S-enyl-2'(or 3')-methyl- 4'(or 5')-cyclopcntadienyl-methane 9.7 mnoles.

Temperature 0C Polymerization time 9 minutes After coagulating and drying 13.7 g of elastomer were obtained; at X-rays examination it was resulted entirely amorphous, and showed the properties given on the Table VIII.

b. The above sample was mixed with carbon black I-IAF (50 parts for 100 parts of polymer) in an open mill, at room temperature; then the obtained mix was moulded at 190C. for 20 minutes.

On the Table VIII there are reported the traction EXAMPLE 7 a. An ethylene-propylene-2-norbor-5-enyl-3'-pentadiene (l',4')-yl-methane was prepared according to the process of the Example 1, paragraph 4, using:

toluene 1000 cm VO(On-C H,), 0.8 mmoles (C,H,),AICI 8 mmoles 2-norbor-5 -enyl-3 '-pentadiene (l',4 )yl-methane 6.5 mmoles (2 mmoles were introduced at the beginning and the test was added minute by minute along the reaction time) 2.0 moles in the gaseous phase a e a":

Temperature Polymerization time minutes After the reaction solution had been coagulated and the polymer has been dried, 17 gr of elastomer were obtained; at X-ray examination it resulted entirely a. An ethylene-propylene-2(or 3)-a1lyldicyclopentadiene terpolymer was synthesized according to the process described in the Example 1, using:

data referring to the dumbell test pieces obtained from amorphous, and it showed the properties given on the the molded plates. Table X.

TABLE VIII Polymer added with carbon black IIAF p.p.e.) and moulded at 190 C. for 20 minutes Ethylene M 50% CR Terpolymer having Tennononier (percent [1:] tol (kg./ (kgJ AR 1. set as termonomer (mole/kg.) b. \v.) 30 C enifi) 0111. (percent) (percent) NOTE: H4=2-norbor-5-enyl-2 (or 3)-methyl-L (or 5')-cyclopentadienylniethane.

TABLE IX Polymer added with carbon black IIAF (50 p.p.e.) and moulded at 100 C. for .20 minutes Ethylene M 50% CR Terpolymer having Termonomer (percent) [11] tel (kgJ (kgJ AR 1. set as termonoiner (mole/kg.) b. \v.) 30 C. em!) 0111. (percent) (percent) N OTE: A2=2(01 3)-allyldieyelopentadiene.

EXAMPLE 6 b. The above sample was mixed with carbon black 65 HAF (50 parts for 100 parts of polymer) in an open mill at room temperature, and then the mix was moulded at C. for 20 minutes.

On the Table X we report the traction data referring to the dumbell test pieces obtained from the plates molded as above.

TABLE X in which R, R R R and R are selected from the group consisting of hydrogen and hydrocarbon radicals Terpolymer ethylene-propylene 2-1rorbor-fi-enyl-l-pentadien (1 ,4)-yl-methane added with carbon black HAF (50 p.p.c.=50 parts for 100 parts of elastoniers), heated in press at. 190 C. for minutes Ethylene M 200% Terpolymer having Termonomer (percent) [1 tel (kgJ (kgJ AR 1. set as termonomer (mole/kg.) b. w.) C. em!) 0111. (kg/cur?) (percent) NOTE: X1=2-norbor-5-enyl-3-penltalyen(l', 4')-yl-1nethune.

WHAT IS CLAIMED IS: which contain from one to five carbon atoms.

1. The method of preparing a vulcanized polymer which comprises heating to a temperature in the range of 150C to 250C, in the absence of any vulcanizing agent or accelerator, a linear terpolymer of two different alpha olefins having up to 10 carbon atoms and a polyene, said linear terpolymer being characterized by side chains that are selected from the group represented by the following formula:

3. The method of preparing a vulcanized polymer according to claim 1 wherein one of the alpha olefins is ethylene.

4. The method of preparing a vulcanized polymer according to claim 3 wherein the second alpha olefin is propylene.

5. The method of preparing a vulcanized polymer ac- 20 cording to claim 1 wherein the polyene is a member of the group represented by the following formulas:

OHz=CH-(CHz)zCH=CHCHz-C=CH= V h CH1 6. The method of preparing a vulcanized polymer according to claim 4 wherein the polyene is dehydrodicyclopentadiene.

7. The method of preparing a vulcanized polymer according to claim 4 wherein the polyene is 2-norbor-5- enyl-2' (or 3')-methyl-4' (or 5 )-cyclopentadienylmethane.

8. The method of preparing a vulcanized polymer according to claim 4 wherein the polyene is 2 (or 3)-a1lyldi-cyclopentadiene.

9. The method of preparing a vulcanized polymer according to claim 4 wherein the polyene is 2-norbor-5- enyl-3pentadiene (l',4)yl-methane.

10. A vulcanized polymer prepared according to the process of claim 1.

11. The combination of a vulcanized polymer as 5 claimed in claim 10 and an extender therefor.

ii I

A T373533 UNITED STATES PATE or or CERTIFICATE or e Patent ha e. 3,691,141 Dated Segtember 1.2 1922 Inventor) Giorgio Corradini, et al It is certified thet error appears in the elove identified patent and that said Letters Psrent are hereby correcred as shown below:

Column 2, line 17-, and Column 10, line 22, correct the first formula 'in each occurrence as follows:

Colman .3, line 13, change"[ to E] Column 5, Table IV, under sub-heading "Terpolymer having as Monomer" correct the formula as follows:

Column 7, line 28, change "mm to read --cm line .37 delete "resulted". 7 Signed and sealed this 26th day of March 1974.

(SEAL) Attest:

EDWARD M.FLETCHER',JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

2. The method of preparing a vulcanized polymer according to claim 1 wherein the side chains of said terpolymer are members of the group represented by the formula:
 3. The method of preparing a vulcanized polymer according to claim 1 wherein one of the alpha olefins is ethylene.
 4. The method of preparing a vulcanized polymer according to claim 3 wherein the second alpha olefin is propylene.
 5. The method of preparing a vulcanized polymer accordiNg to claim 1 wherein the polyene is a member of the group represented by the following formulas:
 6. The method of preparing a vulcanized polymer according to claim 4 wherein the polyene is dehydrodicyclopentadiene.
 7. The method of preparing a vulcanized polymer according to claim 4 wherein the polyene is 2-norbor-5-enyl-2'' (or 3'')-methyl-4'' (or 5'')-cyclopentadienyl-methane.
 8. The method of preparing a vulcanized polymer according to claim 4 wherein the polyene is 2 (or 3)-allyldi-cyclopentadiene.
 9. The method of preparing a vulcanized polymer according to claim 4 wherein the polyene is 2-norbor-5-enyl-3''-pentadiene (1'', 4'')-yl-methane.
 10. A vulcanized polymer prepared according to the process of claim
 1. 11. The combination of a vulcanized polymer as claimed in claim 10 and an extender therefor. 